It's about five-and-a-half times as heavy as a Tennis Ball
In other words, 0.680 pounds is 5.350 times the weight of a Tennis Ball, and the weight of a Tennis Ball is 0.1870 times that amount.(ITF Standard; for Type 2 ball)
Per International Tennis Federation standard, regulation tennis balls must weigh about 0.1270 pounds. Competition balls are also tested for bounce height, with the standards requiring that a ball dropped from 254 cm must bounce back to a height of 135 cm to 147 cm.
It's about six-and-a-half times as heavy as a Golf Ball
In other words, 0.680 pounds is 6.7150 times the weight of a Golf Ball, and the weight of a Golf Ball is 0.14890 times that amount.(per R&A USGA Rules of Golf; maximum rule weight)
According to the Rules of Golf (as approved by the United States Golf Association and the Rules Committee of the Royal and Ancient Golf Club of Saint Andrews), golf balls must weigh no more than 0.10130 pounds. Golf balls are not required to have the familiar dimpled pattern, but the design has been popular since its invention in 1905 because it reduces drag while increasing lift.
It's about one-tenth as heavy as a Chihuahua
In other words, 0.680 pounds is 0.1370 times the weight of a Chihuahua, and the weight of a Chihuahua is 7.30 times that amount.(a.k.a. Chihuahue(o) (FCI standard)
The F&d&ration Cynologique Internationale (FCI) calls for Chihuahuas to weigh about 4.960 pounds. Relative to their body sizes, Chihuahuas have the largest brain size of any dog breed.
It's about one-tenth as heavy as a Brick
In other words, 0.680 pounds is 0.110 times the weight of a Brick, and the weight of a Brick is 9.10 times that amount.(Standard, traditional face brick - 1,900 cu. cm (120 cu. in))
A standard, traditional face brick weighs an average of 6.40 pounds. The steeple of the Church of St. Martin in Landshut, Germany is said to be the tallest brick tower in the world at a height of 130.6 m (428.5 ft) and was constructed using an estimated 650,000 bricks.
It's about nine times as heavy as a Light Bulb
In other words, 0.680 pounds is 9.10 times the weight of a Light Bulb, and the weight of a Light Bulb is 0.110 times that amount.(a.k.a. lamp) (for A19-size, 60w, incandescent bulb by Bulbrite; package weight)
A standard, sixty-watt light bulb weighs about 0.075 pounds. The tightly-coiled filament inside a bulb of this size would measure about 579mm if uncoiled and stretched out.
It's about thirteen times as heavy as a Battery (AA)
In other words, the weight of a Battery (AA) is 0.077 times 0.680 pounds.(Alkaline)
An "AA" size battery weighs 0.053 pounds. AA batteries came into common use during World War II and were given their name by the American National Standards Institute (ANSI) Committee C18 because they were smaller than the "A" size batteries which were invented first.
It's about one-fifteenth as heavy as a Cat
In other words, the weight of a Cat is 10 times 0.680 pounds.(Felis catus) (Domestic; healthy weight)
The average domestic cat should weigh between 10 pounds. Cats are known for their righting reflex, which allows them to land on their feet and survive falls from heights of 1 m (3 ft) up to about 21 m.